Alternator Question

Colombian · 01-08-2010, 10:40 AM

I have a 92 325is and my alternator or the voltage regulator is busted. From what i been reading is better to change the whole thing intead of just the regulator due to the age of the car if that is the sole problem. I just wondering if i should be using a 80 amp or the 140 amp or if it does not matter which one u use and go with the big one. THanks

Dr. Flyview · 01-08-2010, 03:00 PM

The bigger one will be better if you're gonna add a sound system, etc. It won't affect anything except how much current it puts out so bigger the better.

aaron320i · 01-10-2010, 01:58 AM

5speed - 80amp
Automatic- 120amp

tg07lq · 01-10-2010, 03:24 AM

i need a new alternator too i think.
want a hand with yours. haha that way i know what im doing when i do mine! im willing to help

Ceeker · 01-10-2010, 07:27 AM

it is not entirely true; you can over charge the battery having a higher voltage alternator. over charging the system isn't a good thing. Now if you have enough draw on the system such as a sound system then a higher amp alternator should work.

aaron320i · 01-10-2010, 11:57 AM

They do not make batteriers that cannot handle what a car is supposed to push, therefore you really wouldn't be over charging the system, not to mention you over charge a system with voltge not amperage.

I just put a 120 amp in my car last night and it's pushing 14.4v therefore not over charging. Also if you need any help let me know.

rdtx2005 · 01-10-2010, 12:40 PM

i have a spare 80 amp alternator if u r interested... pm me

Ceeker · 01-10-2010, 12:44 PM

Quote:

Originally Posted by Ceeker

it is not entirely true; you can over charge the battery having a higher voltage alternator. over charging the system isn't a good thing. Now if you have enough draw on the system such as a sound system then a higher amp alternator should work.

yes! I stand corrected...you're right voltage is not amperage.

tg07lq · 01-11-2010, 12:15 AM

how hard is the alt swap? my voltage is allll over the place (as per the obc) and the other night i was undergoing sever voltage drops for no good reason at idle

aaron320i · 01-11-2010, 01:34 AM

1. Disconnect battery.
2. Release belt tension.
3. Remove air box and intake.
4. Remove alternator cooling duct.
5. Remove Idler pully/ upper alternator bolt.
6. Remove lower bolt.
7. Wiggler alternator out of place.
8. Disconnect 2 wires on the backside of alternator.
9. Remove alternator.

Reinstall.

EASY

Colombian · 01-11-2010, 06:07 AM

nah.. i think it was pretty easy. afternoon worth of work. i have it all apart and waiting on some parts. got a coolant leak on the lower hose and planning on changing the cooling lines which are showing sign of leakeage. i think the hardest part will be putting the belt back in place under tension..

cheers

Colombian · 01-17-2010, 12:59 PM

k.. i successfully chaged the alternator and the car is back up and running. now the only problem is that now i have some serious noice comming from the engine and it sounds like is somewhere in the belt or pulleys. any ideas what can be done. i put both tensiners is the original place and put the belt back in place. i did notice that there was a little bit of coolant in one of the pulleys, tried to cleaned it but there was a little left int he tracks...

any ideas.. is there any lubricant needed for the belt?

thanks

Ceeker · 01-17-2010, 02:33 PM

sounds like your water pump is going and the dripping coolant is getting on the belts. Or it's the belt tensioner starting to seize. Very common on those cars.

Colombian · 01-17-2010, 08:24 PM

well the coolant in the pulleys can be explained as also just changed the upper and lower rad hoses and retighten the coolant expansion tank hose bc i had a leak in the system. coolant spilled and got inside the pulleys. i tried to clean it as much as i could but there were some fluid within the tracks. i figure it will evaporate when the car is on and was no big deal. prior to changing the alternator the car had no noices. i marked the running mark for the belt and took it off by removing two pulleys. it was pretty touugh to get the belt back on but its in there pretty tight. the car starts with a whistling noice barely noticeable and gets a little louder but at a higher picht as u accelerate. sometimes you hear some rattling. I put some belt dressing and the noices seemed to disappear. after driving the car around the block the noices and rattling come back.

I guess it could be the pulleys but what bothers me is that the car was not making any noices prior to removal of the belt. I think it is the stock one so a new belt is probably required. Does anyone has a DIY for checking the water pump. I am not sure if it has been replaced or not and I would like to check its condition.

Thanks